Arto's String Calculator very comprehensive online program with full instructions for calculating where a string can be used by setting the diameter and more. Measures string tension and diameter for a number of instruments, in a variety of settings.

Java Tuner This Java applet demonstrates various historical tunings and temperaments and allows one to experiment with them. It was developed to accompany a text on Understanding temperaments, and is complemented by a set of MIDI files demonstrating various tunings and temperaments, full instructions and a variety of modern and archaic tuning modes. Also provides selected intervals and a chord player.

String Guage & Tension Calculator Check your string tensions based on pitch, guage and type of string, also does the inverse calculation when you type in other string parameters.